valentine



Sept. 9. 1924. 1,508,374

I. R. VALENTINE ELECTRIC MUFFLE FURNACE Filed Oct. 13. '1920- lnx/enbor'rf Irving R. Valenth e,

His Abba? nay- Patented Sept. 9, 1924.

UNITED STATES PATENT OFFICE.

IRVING R. VALENTINE, OF ERIE, PENNSYLVANIA, ASSIGNOR T GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC M'UFFLE FURNACE.

Application filed October 13, 1920. Serial 1T0. 416,669.

To all whomit may concern:

Be it known that I, IRVING R. VALENTINE, a citizen of the United States, residing at Erie, county of Erie, State of Pennsylvania, have invented certain new and useful. Improvements in Electric Mufile Furnaces, of

V which the following is a specification.

melting easily fusible metals, warming air.

and so forth.

In order to carry out heating operations such as these, it is not necessary t 'usean electriohenter adapted to be raised to n yery high temperature- I have devised a furnace adapted to deliver a heating cur;

rent of suiiiciently large amperage to heat a massive resistor consisting of a common metal, for example, iron, to the required temperature. At theoperating temperatures required for this class of operations such a heater is indestructible for practical purposes.

In the accompanying drawing, Fig. 1 is a perspective view of a furnace embodying my invention, and Fig. 2 is a vertical section.

The furnace, as shown in the drawing. comprises an electric resistor 1 consisting of a massive bar or casting of iron, nickel, or other suitable metal. In some cases the iron may be calorized, that is, provided with an oxidation resisting surface alloy of aluminum. It is bent upon itself in the form of a rectangular loop, the lower sections being separated by a strip 2. of suitable insulating material. Either integral with the heater loop 1, or conductively connected thereto is a conductor loop 3, constituting the secondary winding of a transformer. This loop 3 is inductively linked with a magnetic core 4, which is provided with a primary winding 5. The secondary 3, preferablv is water-cooled, as indicated in Fig. 1, by the cooling pipe 6. Surrounding the heater loop is a heat insulating housing 7, consisting of fire-brick, or other suitable refractory material. The mu'flle constituted by the housing 7 and the heater 1 is supported oncolumns 8, the core and primary' winding being" suspended beneath the furnace, as indicated.

What I claim as new and desire to secure by Letters Patent of the United States, is, 1. A m'uflle furnace comprising a heating chamber, a loop shaped casting of iron constituting part of the wall of said chamber, and transformer means connected to said loop for furnishing a heating current thereto.

2-. A mufiie furnace comprising a heating chamber, a-loop shaped casting of iron constituting part of the wall of said chamber, and transformenmeans depending from said 0 ne ed... t the sepsis .1'11}. TQf..- f

furnishing a heating (3' entt ran; 3. A muflle furnace comprising a plat form, a heating chamber thereon, part of the wall of which is constituted by a casting of iron constituting a nearly closed loop having inwardly projecting ends, refractory insulating material separating said ends and transformer means constituting a part of said furnace connected to the ends of said loop for furnishing a heating current to said 100 4 An electric mnflle furnace comprising a heater consisting of a conductor which is sufiiciently massive to be selfsupporting. and which is bent upon itself to enclose a heating space, a. heat insulating housing surrounding said heater, a transformer core adjacent said heater, 2. primary winding thereon, and means for interlinking said heater circuit with said core.

5. A muflie furnace comprising a casting of iron bent upon'itself in the form of a substantially rectangular loop, a heat insulating housing therefor, a spacer of electrical insulating material separating the contiguous ends of said loop, a supporting column for said furnace, a transformer core supported by said column beneath said furnace, a primary winding on said core, and a conductor interlinked with said core and connected to the ends of said loop.

In witness whereof, I have hereunto set my hand this 11th day of October, 1920.

IRVING R. VALENTINE. 

